1. Field
The disclosed subject matter pertains to semiconductor fabrication and, more particularly, wafer level bonding processes.
2. Related Art
In the field of semiconductor devices, packaging considerations may be driven, at least in part, by the type of device being packaged. Micro-electrical-mechanical systems (MEMS), for example, include devices, fabricated using known semiconductor process techniques, employing structures that implement some type of mechanical function.
Wafer level bonding is generally employed to achieve a first level package for MEMS devices. Wafer level bonding refers to a process in which two wafers, at least one of which includes a semiconductor device, are bonded together. An example of a conventional wafer level bonding process is glass frit bonding. Glass frit bonding includes screen printing a frit material onto a substrate of one of the wafers prior to alignment and thermal bonding. The glass frit tends to shrink during bonding, resulting in non-uniform bondline dimensions. In addition, the deposited frit material consumes an amount of wafer real estate that prohibits or competes with device scaling desirable for achieving lower manufacturing costs.